is work is still in progress and consists of assessing the biosynthesis of tracellular matrix and the morphological appearance of a tumor cell line 549) and normal skin fibroblasts in a matrix synthesized by a cell line HS). The cells are plated on the surface of a layer of the pre-formed tracellular matrix, mixed within the pre-formed matrix, or overlayed by the e-formed matrix. A549 cells alone, in combination with fibroblasts or broblasts alone, are studied in each of these locations.